Falke, who was born in Westerholt, Westphalia became a glider pilot in 1929 before he joined the Lufthansa. In 1932, he graduated as a pilot at the Deutsche Verkehrsfliegerschule (German Commercial Flyers' School) in Braunschweig before applying to join the Reichswehr of the Weimar Republic later in the year. Falke's application was accepted, but he never took up the offer. In February 1934, he was transferred to the Luftwaffe. In 1937, during the Spanish Civil War, he volunteered for the Condor Legion and flew ground attack missions in support of the Nationalists under Francisco Franco. After finishing his tour in 1938 Falke was employed in the Air Ministry writing doctrinal and technical manuals about his experiences as a ground-attack pilot. During this period Falke served as an instructor for ground-attack units. During the German invasion of Poland in September 1939, he again flew ground attack missions. In early 1940, Falke managed to persuade his superiors to allow him to become a fighter pilot.